1. Field of the Invention
This invention relates to an apparatus for fabrication of contacts for use with electrical circuits, and particularly relates to an apparatus for attaching an electrical contact to a metal member, and more particularly relates to an apparatus for welding a contact element to a metal member to produce an electrical contact suitable for fabricating electrical sockets or terminals.
2. Description of the Prior Art
Electrical sockets and terminals for establishing electrical contact are well known in the prior art. The general requirements for such sockets and terminals are that they have surfaces for establishing electrical contact and resisting corrosion and wear. It is well known to gold plate the interior surfaces of a socket or the outer surface of a terminal to insure good electrical contact. However, the gold plating process of the prior art is both expensive and inefficient. Whether the strip material from which the sockets or terminals are to be fabricated is coated on one or both sides, the amount of gold applied to the surface is greater than is actually required for establishing good electrical contact. In an effort to decrease the amount of gold used and to insure good electrical contact between sockets and terminals, either the sockets or terminals or both have been fabricated from base metal strips having a small raised gold contact or dot welded on what is to become the contact surface of the socket or terminal. Although this latter type of socket or terminal provides for substantial economy in conserving the amount of gold required for providing electrical contact in sockets and terminals, it requires either substantial manual processing operations or complex and expensive automatic equipment. Various apparatus for welding electrical contacts to strip stock are described in U.S. Pat. Nos. 3,114,828; 3,299,246 and 3,382,575. All the aforementioned apparatus include mechanical cutters for severing the welded contact from the strip material. Another method and apparatus using ultrasonic welding techniques is disclosed in U.S. Pat. No. 3,357,909, and uses a flame to cut a wire welded to a stock member.